Image-distorting endoscopes and methods of making and using such endoscope

ABSTRACT

An endoscope having restricted dimensions and comprising at least one image gatherer, at least one image distorter and at least one image sensor shaped to fit within said limited dimensions, and wherein said image distorter is operable to distort an image received from said image gatherer so that the image is sensible at said shaped image sensor.

RELATED PATENT APPLICATIONS

This application is a Divisional Patent Application of U.S. ApplicationSer. No. 09/826,163 filed Apr. 5, 2001, now U.S. Pat. No. 6,659,940,which claims priority from Israel Patent Application No. 135571 filedApr. 10, 2000.

FIELD OF THE INVENTION

The present invention relates to an image sensor, and more particularlybut not exclusively to two and three-dimensional optical processing fromwithin restricted spaces, and an endoscope using the same.

BACKGROUND OF THE INVENTION

Endoscopy is a surgical technique that involves the use of an endoscope,to see images of the body's internal structures through very smallincisions.

Endoscopic surgery has been used for decades in a number of differentprocedures, including gall bladder removal, tubal ligation, and kneesurgery, and recently in plastic surgery including both cosmetic andre-constructive procedures.

An endoscope may be a rigid or flexible endoscope which consists of fivebasic parts: a tubular probe, a small camera head, a camera controlunit, a bright light source and a cable set which may include a fiberoptic cable. The endoscope is inserted through a small incision; andconnected to a viewing screen which magnifies the transmitted images ofthe body's internal structures.

During surgery, the surgeon is able to view the surgical area bywatching the screen while moving the tube of the endoscope through thesurgical area.

In a typical surgical procedure using an endoscope, only a few smallincisions, each less than one inch long, are needed to insert theendoscope probe and other instruments. For some procedures, such asbreast augmentation, only two incisions may be necessary. For others,such as a forehead lift, three or four short incisions may be needed.The tiny eye of the endoscope camera allows a surgeon to view thesurgical site.

An advantage of the shorter incisions possible when using an endoscopeis reduced damage to the patient's body from the surgery. In particular,the risk of sensory loss from nerve damage is decreased. However, mostcurrent endoscopes provide only flat, two-dimensional images which arenot always sufficient for the requirements of the surgery. The abilityof an endoscope to provide three-dimensional information in its outputwould extend the field of endoscope use within surgery.

The need for a 3D imaging ability within an endoscope has been addressedin the past. A number of solutions that provide stereoscopic images byusing two different optical paths are disclosed in Patents U.S. Pat.Nos. 5,944,655, 5,222,477, 4,651,201, 5,191,203, 5,122,650, 5,471,237,JP7163517A, U.S. Pat. Nos. 5,673,147, 6,139,490, 5,603,687, WO9960916A2,and JP63244011A.

Another method, represented by U.S. Patents, U.S. Pat. Nos. 5,728,044and 5,575,754 makes use of an additional sensor that provides locationmeasurements of image points. Patent JP8220448A discloses a stereoscopicadapter for a one-eye endoscope, which uses an optical assembly todivide and deflect the image to two sensors. A further method, disclosedin U.S. Pat. No. 6,009,189 uses image acquisition from differentdirections using one or more cameras. An attempt to obtain 3Dinformation using two light sources was disclosed in U.S. Pat. No.4,714,319 in which two light sources are used to give an illusion of astereoscopic image based upon shadows. JP131622A discloses a method forachieving the illusion of a stereoscopic image by using two lightsources, which are turned on alternately.

An additional problem with current endoscopes is the issue of lightingof the subject for imaging. The interior spaces of the body have to beilluminated in order to be imaged and thus the endoscope generallyincludes an illumination source. Different parts of the field to beilluminated are at different distances from the illumination source andrelative reflection ratios depend strongly on relative distances to theillumination source. The relative distances however may be very large Ina typical surgical field of view, distances can easily range between 2and 20 cm giving a distance ratio of 1:10. The corresponding brightnessratio may then be 1:100, causing blinding and making the more distantobject all but invisible.

One reference, JP61018915A, suggests solving the problem of unevenlighting by using a liquid-crystal shutter element to reduce thetransmitted light. Other citations that discuss general regulation ofillumination levels include U.S. Pat. No. 4,967,269, JP4236934A,JP8114755A and JP8024219A.

In general it is desirable to reduce endoscope size and at the same timeto improve image quality. Furthermore, it is desirable to produce adisposable endoscope, thus avoiding any need for sterilization, it beingappreciated that sterilization of a complex electronic item such as anendoscope being awkward in itself.

Efforts to design new head architecture have mainly concentrated onintegration of the sensor, typically a CCD based sensor, with optics atthe distal end. Examples of such integration are disclosed in U.S. Pat.Nos. 4,604,992, 4,491,865, 4,692,608, JP60258515A, U.S. Pat. Nos.4,746,203, 4,720,178, 5,166,787, 4,803,562, 5,594,497 and EP434793B1.Reducing the overall dimensions of the distal end of the endoscope areaddressed in U.S. Pat. Nos. 5,376,960 and 4,819,065, and Japanese PatentApplications No. 7318815A and No. 70221A. Integration of the endoscopewith other forms of imaging such as ultrasound and Optical CoherenceTomography are disclosed in U.S. Pat. Nos. 4,869,256, 6,129,672,6,099,475, 6,039,693, 55,022,399, 6,134,003 and 6,010,449

Intra-vascular applications are disclosed in certain of theabove-mentioned patents, which integrate the endoscope with anultrasound sensor or other data acquisition devices. Patents thatdisclose methods for enabling visibility within opaque fluids are U.S.Pat. Nos. 4,576,146, 4,827,907, 5,010,875, 4,934,339, 6,178,346 and4,998,972.

Sterilization issues of different devices including endoscopes arediscussed in WO9732534A1, U.S. Pat. Nos. 5,792,045 and 5,498,230. Inparticular JP3264043A discloses a sleeve that was developed in order toovercome the need to sterilize the endoscope.

The above-mentioned solutions are however incomplete and are difficultto integrate into a single endoscope optimized for all the above issues.

SUMMARY OF THE INVENTION

It is an aim of the present embodiments to provide solutions to theabove issues that can be integrated into a single endoscope.

It is an aim of the embodiments to provide an endoscope that is smallerthan current endoscopes but without any corresponding reduction inoptical processing ability.

It is a further aim of the present embodiments to provide a 3D imagingfacility that can be incorporated into a reduced size endoscope.

It is a further aim of the present embodiments to provide objectillumination that is not subject to high contrast problems, for exampleby individual controlling of the light sources.

It is a further aim of the present embodiments to provide a modifiedendoscope that is simple and cost effective to manufacture and maytherefore be treated as a disposable item.

Embodiments of the present invention provide 3D imaging of an objectbased upon photometry measurements of reflected light intensity. Such amethod is relatively efficient and accurate and can be implementedwithin the restricted dimensions of an endoscope.

According to a first aspect of the present invention there is thusprovided a pixilated image sensor for insertion within a restrictedspace, the sensor comprising a plurality of pixels arranged in aselected image distortion pattern, said image distortion pattern beingselected to project an image larger than said restricted space to withinsaid restricted space substantially with retention of an imageresolution level.

Preferably, the image distortion pattern is a splitting of said imageinto two parts and wherein said pixilated image sensor comprises saidpixels arranged in two discontinuous parts.

Preferably, the discontinuous parts are arranged in successive lengths.

Preferably, the restricted space is an interior longitudinal wall of anendoscope and wherein said discontinuous parts are arranged onsuccessive lengths of said interior longitudinal wall.

Preferably, the restricted space is an interior longitudinal wall of anendoscope and wherein said discontinuous parts are arranged onsuccessive lengths of said interior longitudinal wall.

Preferably, the distortion pattern is an astigmatic image distortion.

Preferably, the distortion pattern is a projection of an image into arectangular shape having dimensions predetermined to fit within saidrestricted space.

A preferred embodiment includes one of a group comprising CMOS-basedpixel sensors and CCD based pixel sensors.

A preferred embodiment is controllable to co-operate with alternatingimage illumination sources to produce uniform illuminated images foreach illumination source.

According to a second aspect of the present invention there is providedan endoscope having restricted dimensions and comprising at least oneimage gatherer at least one image distorter and at least one imagesensor shaped to fit within said restricted dimensions, and wherein saidimage distorter is operable to distort an image received from said imagegatherer so that the image is sensible at said shaped image sensorsubstantially with an original image resolution level.

Preferably, the image distorter comprises an image splitter operable tosplit said image into two part images.

Preferably, the image sensor comprises two sensor parts, each separatelyarranged along longitudinal walls of said endoscope.

Preferably, the two parts are arranged in successive lengths alongopposite longitudinal walls of said endoscope.

Preferably, the distorter is an astigmatic image distorter.

Preferably, the astigmatic image distorter is an image rectangulator andsaid image sensor comprises sensing pixels rearranged to complementrectangulation of said image by said image rectangulator.

Preferably, the image distorter comprises at least one lens.

Preferably, the image distorter comprises at least one image-distortingmirror.

Preferably, the image distorter comprises optical fibers to guide imagelight substantially from said lens to said image sensor.

Preferably, the image distorter comprises a second lens.

Preferably, the image distorter comprises at least a secondimage-distorting mirror.

Preferably, the image distorter comprises at least one flat opticalplate.

A preferred embodiment comprises at least one light source forilluminating an object, said light source being controllable to flash atpredetermined times.

A preferred embodiment comprises a second light source, said first andsaid second light sources each separately controllable to flash.

Preferably, the first light source is a white light source and saidsecond light source is an IR source.

In a preferred embodiment, one light source being a right side lightsource for illuminating an object from a first side and the other lightsource being a left side light source for illuminating said object froma second side.

In a preferred embodiment, one light source comprising light of a firstspectral response and the other light source comprising light of asecond spectral response.

A preferred embodiment further comprises color filters associated withsaid light gatherer to separate light from said image into right andleft images to be fed to respective right and left distance measurers toobtain right and left distance measurements for construction of athree-dimensional image.

In a preferred embodiment, said light sources are configured to flashalternately or simultaneously.

A preferred embodiment further comprises a relative brightness measurerfor obtaining relative brightnesses of points of said object usingrespective right and left illumination sources, thereby to deduce 3dimensional distance information of said object for use in constructionof a 3 dimensional image thereof.

A preferred embodiment further comprises a second image gatherer and asecond image sensor.

Preferably, the first and said second image sensors are arranged back toback longitudinally within said endoscope.

Preferably, the first and said second image sensors are arrangedsuccessively longitudinally along said endoscope.

Preferably, the first and said second image sensors are arranged along alongitudinal wall of said endoscope.

A preferred embodiment comprises a brightness averager operable toidentify brightness differentials due to variations in distances fromsaid endoscope of objects being illuminated, and substantially to cancelsaid brightness differentials.

A preferred embodiment further comprises at least one illuminationsource for illuminating an object with controllable width light pulsesand wherein said brightness averager is operable to cancel saidbrightness differentials by controlling said widths.

A preferred embodiment has at least two controllable illuminationsources, one illumination source for emitting visible light to produce avisible spectrum image and one illumination source for emittinginvisible (i.e. IR or UV) light to produce a corresponding spectralresponse image, said endoscope being controllable to produce desiredratios of visible and invisible images.

According to a third aspect of the present invention there is providedan endoscope system comprising an endoscope and a controller, saidendoscope comprising:

at least one image gatherer,

at least one image distorter and

at least one image sensor shaped to fit within restricted dimensions ofsaid endoscope, said image distorter being operable to distort an imagereceived from said image gatherer so that the image is sensible at saidshaped image sensor with retention of image resolution,

said controller comprising a dedicated image processor for processingimage output of said endoscope.

Preferably, the dedicated image processor is a motion video processoroperable to produce motion video from said image output.

Preferably, the dedicated image processor comprises a 3D modeler forgenerating a 3D model from said image output.

Preferably, the said dedicated image processor further comprises a 3Dimager operable to generate a stereoscopic display from said 3D model.

A preferred embodiment comprises an image recorder for recordingimaging.

A preferred embodiment comprises a control and display communicationlink for remote control and remote viewing of said system.

Preferably, the image distorter comprises an image splitter operable tosplit said image into two part images.

Preferably, the image sensor comprises two sensor parts, each separatelyarranged along longitudinal walls of said endoscope.

Preferably, the two parts are arranged in successive lengths alongopposite longitudinal walls of said endoscope.

Preferably, the distorter is an astigmatic image distorter.

Preferably, the astigmatic image distorter is an image rectangulator andsaid image sensor comprises sensing pixels rearranged to complementrectangulation of said image by said image rectangulator.

Preferably, the image distorter comprises at least one lens.

Preferably, the image distorter comprises at least one image-distortingmirror.

Preferably, the image distorter comprises optical fibers to guide imagelight substantially from said lens to said image sensor.

Preferably, the image distorter comprises a second lens.

Preferably, the image distorter comprises at least a secondimage-distorting mirror.

Preferably, the image distorter comprises at least one flat opticalplate.

A preferred embodiment further comprises at least one light source forilluminating an object.

A preferred embodiment comprises a second light source, said first andsaid second light sources each separately controllable to flash.

Preferably, the first light source is a white light source and saidsecond light source is an invisible source.

In a preferred embodiment, one light source is a right side light sourcefor illuminating an object from a first side and the other light sourceis a left side light source for illuminating said object from a secondside.

In a preferred embodiment, one light source comprises light of a firstspectral response and the other light source comprises light of a secondspectral response.

A preferred embodiment comprises color filters associated with saidlight gatherer to separate light from said image into right and leftimages to be fed to respective right and left distance measurers toobtain right and left distance measurements for construction of athree-dimensional image.

Preferably, the light sources are configured to flash alternately orsimultaneously.

A preferred embodiment further comprises a relative brightness measurerfor obtaining relative brightnesses of points of said object usingrespective right and left illumination sources, thereby to deduce 3dimensional distance information of said object for use in constructionof a 3 dimensional image thereof.

A preferred embodiment further comprises a second image gatherer and asecond image sensor.

Preferably, the first and said second image sensors are arranged back toback longitudinally within said endoscope.

Preferably, the first and said second image sensors are arrangedsuccessively longitudinally along said endoscope.

Preferably, the first and said second image sensors are arranged along alongitudinal wall of said endoscope.

A preferred embodiment comprises a brightness averager operable toidentify brightness differentials due to variations in distances fromsaid endoscope of objects being illuminated, and substantially to reducesaid brightness differentials.

According to a fifth embodiment of the present invention there isprovided an endoscope for internally producing an image of a field ofview, said image occupying an area larger than a cross-sectional area ofsaid endoscope, the endoscope comprising:

an image distorter for distorting light received from said field of viewinto a compact shape, and

an image sensor arranged in said compact shape to receive said distortedlight to form an image thereon.

A preferred embodiment comprises longitudinal walls, wherein said imagesensor is arranged along said longitudinal walls, the endoscope furthercomprising a light diverter for diverting said light towards said imagesensor.

Preferably, the image sensor comprises two parts, said distortercomprises an image splitter for splitting said image into two parts, andsaid light diverter is arranged to send light of each image part to arespective part of said image sensor.

Preferably, the sensor parts are aligned on facing lengths of internalsides of said longitudinal walls of said endoscope.

Preferably, the sensor parts are aligned successively longitudinallyalong an internal side of one of said walls of said endoscope.

A preferred embodiment of the image distorter comprises an astigmaticlens shaped to distort a square image into a rectangular shape ofsubstantially equivalent area.

A preferred embodiment further comprises a contrast equalizer forcompensating for high contrasts differences due to differentialdistances of objects in said field of view.

A preferred embodiment comprises two illumination sources forilluminating said field of view.

In a preferred embodiment, the illumination sources are controllable toilluminate alternately, and said image sensor is controllable to gatherimages in synchronization with said illumination sources thereby toobtain independently illuminated images.

In a preferred embodiment, each illumination source is of a differentpredetermined spectral response.

A preferred embodiment of said image sensor comprises pixels, each pixelbeing responsive to one of said predetermined spectral responses.

A preferred embodiment of the image sensor comprises a plurality ofpixels responsive to white light.

In a preferred embodiment, said image sensor comprises a plurality ofpixels responsive to different wavelengths of light.

In a preferred embodiment, the wavelengths used comprise at least threeof red light, green light, blue light and infra-red light.

In a preferred embodiment, a second image sensor forms a second imagefrom light obtained from said field of view.

In a preferred embodiment, said second image sensor is placed in back toback relationship with said first image sensor over a longitudinal axisof said endoscope.

In a preferred embodiment, the second image sensor is placed in end toend relationship with said first image sensor along a longitudinal wallof said endoscope.

In a preferred embodiment, the second image sensor is placed across fromsaid first image sensor on facing internal longitudinal walls of saidendoscope.

According to a sixth embodiment of the present invention there isprovided a compact endoscope for producing 3D images of a field of view,comprising a first image sensor for receiving a view of said fieldthrough a first optical path and a second image sensor for receiving aview of said field through a second optical path, and wherein said firstand said second image sensors are placed back to back along alongitudinal axis of said endoscope.

According to a seventh embodiment of the present invention there isprovided a compact endoscope for producing 3D images of a field of view,comprising a first image sensor for receiving a view of said fieldthrough a first optical path and a second image sensor for receiving aview of said field through a second optical path, and wherein said firstand said second image sensors are placed end to end along a longitudinalwall of said endoscope.

According to an eighth embodiment of the present invention there isprovided a compact endoscope for producing 3D images of a field of view,comprising two illumination sources for illuminating said field of view,an image sensor for receiving a view of said field illuminated via eachof said illumination sources, and a view differentiator fordifferentiating between each view.

Preferably, the differentiator is a sequential control for providingsequential operation of said illumination sources.

Preferably, the illumination sources are each operable to produceillumination at respectively different spectral responses and saiddifferentiator comprises a series of filters at said image sensor fordifferentially sensing light at said respectively different spectralresponses.

Preferably, the image distorter comprises a plurality of optical fibersfor guiding parts of a received image to said image sensor according tosaid distortion pattern.

According to a ninth embodiment of the present invention there isprovided a method of manufacturing a compact endoscope, comprising:

providing an illumination source,

providing an image distorter,

providing an image ray diverter,

providing an image sensor whose shape has been altered to correspond toa distortion built into said image distorter, said distortion beingselected to reduce at least one dimension of said image sensor to lessthan that of an undistorted version being sensed,

assembling said image distorter, said image ray diverter and said imagesensor to form an optical path within an endoscope

According to a tenth embodiment of the present invention there isprovided a method of obtaining an endoscopic image comprising:

illuminating a field of view,

distorting light reflected from said field of view such as to form adistorted image of said field of view having at least one dimensionreduced in comparison to an equivalent dimension of said undistortedimage, and

sensing said light within said endoscope using at least one image sensorcorrespondingly distorted.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show how the same maybe carried into effect, reference will now be made, purely by way ofexample, to the accompanying drawings, in which:

FIG. 1 is a simplified block diagram of an endoscope system to whichembodiments of the present invention may be applied,

FIG. 2 is a simplified block diagram of an endoscope system according toa first embodiment of the present invention,

FIG. 3 is a simplified block diagram of a wireless modification of theendoscope of FIG. 2,

FIG. 4 is a simplified schematic block diagram of an endoscope accordingto a preferred embodiment of the present invention,

FIG. 5 is a simplified ray diagram showing optical paths within anendoscope according to a preferred embodiment of the present invention,

FIG. 6 is a ray diagram view from a different angle of the embodiment ofFIG. 5,

FIG. 7 is a ray diagram showing an alternative construction of anoptical assembly according to a preferred embodiment of the presentinvention,

FIG. 8 is a ray diagram showing a further alternative construction of anoptical assembly according to a preferred embodiment of the presentinvention,

FIG. 9 is a ray diagram showing yet a further alternative constructionof the optical assembly according to a preferred embodiment of thepresent invention,

FIG. 10 is a ray diagram taken from the front, of the embodiment of FIG.9,

FIG. 11 is a ray diagram showing yet a further alternative constructionof an optical assembly according to a preferred embodiment of thepresent invention,

FIG. 12 is a simplified layout diagram of an image sensor according toan embodiment of the present invention,

FIG. 13 is a simplified ray diagram showing an endoscope for use in astereoscopic mode according to a preferred embodiment of the presentinvention,

FIG. 14 is a simplified ray diagram showing how a 3D model obtained fromthe embodiment of FIG. 13 can be used to construct a stereoscopic imageof the field of view,

FIG. 15A is a simplified diagram in cross-sectional view showing anarrangement of the image sensors in a stereoscopic endoscope accordingto a preferred embodiment of the present invention,

FIG. 15B is a view from one end of the arrangement of FIG. 15A,

FIG. 16 is a simplified ray diagram showing an alternative arrangementof sensors for obtaining a stereoscopic image of a field of viewaccording to a preferred embodiment of the present invention,

FIG. 17 is a simplified block diagram of a network portable endoscopeand associated hardware usable with preferred embodiments of the presentinvention,

FIG. 18 is a simplified block diagram of an endoscope adapted to performminimal invasive surgery and usable with the preferred embodiments ofthe present invention,

FIG. 19 is a simplified block diagram of an enhanced endoscope systemfor use in research,

FIG. 20 is a simplified block diagram of a configuration of an endoscopesystem for obtaining stereoscopic images, and usable with the preferredembodiments of the present invention, and

FIG. 21 is a simplified block diagram of a system for use inintravascular procedures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present embodiments provide a diagnostic and operative system forminimally invasive diagnosis and surgery procedures, and other medicaland non-medical viewing applications, in particular in which accessconditions dictate the use of small-dimension viewing devices.

Reference is now made to FIG. 1, which is a basic block diagram of abasic configuration of an endoscope according to a first embodiment ofthe present invention. The figure snows a basic configuration of theendoscopic system including interconnections. The configurationcomprises a miniature endoscopic front-end 10, hereinafter simplyreferred to as an endoscope, attached by a wire connection 20 to aprocessing device 30, typically a PC, the PC having appropriate softwarefor carrying out image processing of the output of the endoscope. Theskilled person will appreciate that the wire connection 20 may be anoptical connection or may instead use RF or a like means of wirelesscommunication. The miniature endoscopic front-end 10 may be designed forconnection to any standard PC input (the USB input for example).

The software included with processing device 30 processes the output ofthe miniature endoscopic front-end 10. The software may typicallycontrol transfer of the images to the monitor of the PC 30 and theirdisplay thereon including steps of 3D modeling based on stereoscopicinformation as will be described below, and may control internalfeatures of the endoscopic front end 10 including light intensity, andautomatic gain control (AGC), again as will be described below.

Reference is now made to FIG. 2, which is an internal block diagram ofan endoscope according to a preferred embodiment of the presentinvention. A miniature endoscope 40 is connected by a wire 42 to anadapter 44. The endoscope 40 comprises an image sensor 46 which maytypically comprise a CMOS or CCD or like sensing technology, an opticalassembly 48, a light or illumination source 50, communication interface52 and controller 54. The wired unit of FIG. 2 preferably includes avoltage regulator 56.

As will be explained in more detail below, the image sensor 46 isaligned along the length of a longitudinal side-wall (that is to saysubstantially in parallel with the wall and at least not perpendicularthereto) of the endoscope 40. Such an alignment enables the radialdimension of the endoscope to be reduced beyond the diagonal of theimage sensor 46. Preferably the sensor is arranged in two parts, as willbe explained below.

Reference is now made to FIG. 3, which is an internal block diagram of awireless equivalent of the embodiment of FIG. 2. Parts that areidentical to those shown above are given the same reference numerals andare not referred to again except as necessary for an understanding ofthe present embodiment. In the embodiment of FIG. 3, the wire 42 isreplaced by a wireless link 56 such as an IR or RF link with appropriatesensor, and a battery pack 58.

Reference is now made to FIG. 4, which is an schematic block diagram ofthe miniature endoscope according to a preferred embodiment of thepresent invention. Parts that are identical to those shown above aregiven the same reference numerals and are not referred to again exceptas necessary for an understanding of the present embodiment. Opticalassembly 48 receives light, indicated by arrows 60, from an object beingviewed. The light is processed by optical assembly 48, as will beexplained below, to reach image sensor 46 were it is converted fromphotons into electrical signals. The electrical signals are digitizedand passed to a transmitting device 62, for example an LVDS transmitter,which drives the data through communication link 20 and adapter 44 tothe processing device 30.

Operating power for the endoscope 40 is preferably provided, throughadapter 44, to the voltage regulator 56. Control of the front-end ispreferably carried out by the processor device 30 as discussed above.Control data from the processing device 30 is preferably received at theendoscope 40 by a receiving device 64, which may typically be an LVDSreceiver. Hard wired logic 66 preferably serves as an interface toconvert the incoming control data into signals for controlling both thesensor 46 and the light source 50.

The light source 50 preferably comprises one or more light transmittingdevices such as LEDs, typically a left light source 68 and right lightsource 70. The left and right light sources may be controllable througha driver 72. The functions of each of the above components are describedin greater detail below. As the skilled person will be aware, use ofCMOS and similar technologies for the sensors permit the sensor 46, thetransmitting device 62, the receiving device 64, the hard wired logic66, the driver 72 and the voltage regulator 56 to be integrated into asingle semiconductor Integrated Circuit and such integration isparticularly advantageous in achieving a compact design of endoscope.

Considering the light source 50 in greater detail, it preferablycomprises an integrated array of several white light sources (LEDs forexample) with energy emission in the visible light range mixed,optionally, with IR light sources (LEDs) for purposes that will beexplained below. In fact, any combination of spectral responses may beused, particularly preferred combinations including red+IR andgreen+blue. An integrated array of light sources allows control of eachlight source individually facilitating the following features:

The System is able to turn on the white light source and the IR Lightsource in sequence to generate an IR image every N (user determined)standard white images, for detection by a sensor configuration to bedescribed below with respect to FIG. 12.

The objects being imaged are generally located at a range of differentdistances or field depths from the light source and are consequentlyunevenly illuminated. The more distant areas in the field are dark andare almost invisible while the nearer areas are bright and can becomesaturated. In order to compensate for the uneven illumination intensityover the field, the system preferably exerts control over the intensityof each light source individually, thereby to compensate for reflectedintensity of the objects. An example of an algorithm for control of theillumination array is given as follows:

Given N individual light sources in the illumination array in the camerahead, an initialization process is carried out to generate a referenceimage, preferably a homogeneous white object, to be stored for eachlight source. The stored reference images (matrices) are identifiedhereinbelow by RIi where i=1, 2, . . . N

Following initialization, imaging is carried out and the input image ofthe field (indicated by matrix II) is divided into M areas such that:M>N. The image areas are identified hereinbelow by Sj j=1, 2, . . . M

Following the above imaging stage, an inner product matrix is calculatedsuch that element Tij of the inner product matrix reflects the innerproduct resulting from taking the II matrix and performing matrixmultiplication with the RIi matrix, in the area Sj and summing theelements of the result metrics.

The resulting inner product matrix is given by T where:

M $T = {{\begin{matrix}{t11} & {t12} & \ldots & {t1M} \\{t21} & \ldots & \ldots & {t2M} \\{tN1} & \ldots & \ldots & {tNM}\end{matrix}}N\mspace{14mu}{and}}$${Tij} = {{1/{Sj}}\;{\sum\limits_{P = 1}^{Sj}{{{Pij}\left( {{xp},{yp}} \right)} \cdot {{Rj}\left( {{xp},{yp}} \right)}}}}$wherein

Pij—the intensity of the pixel located in (xp, yp) resulting from lightsource i in area j

Rj—the intensity of the pixel located in (xp, yp) resulting from theinput image in area j

Sj—the total pixels in area j

xp, yp—the pixels coordinates in area j

Next, a vector v is determined that satisfies the following:Tv−k→Min, where

v—the vector of intensities of each source, and

k—the vector of the desired common intensity, and the solution to thisrequirement is given byv =(T ^(T) ·T)⁻¹ ·T ^(T) ·k

The central control unit preferably uses the above algorithm topost-process the data to reconstruct a natural look of the image,thereby to compensate for brightness non-uniformities.

In the case of using LEDs as the light source, their fast response timemakes it possible to operate them in a “controllable-flash” mode,replacing the need for variable integration time (or AGC).

Referring now to the image sensor 46, as observed above in respect ofFIG. 2, in the prior art endoscope the size of the sensor provides alimitation on the transverse diameter of the endoscope. Thus, in thepresent embodiment, in order to remove the limitation the sensor isplaced along the longitudinal wall of the endoscope, again preferablysubstantially parallel to the wall but at least not perpendicularthereto. The use of the longitudinal wall not only gives greater freedomto reduce the transverse diameter of the endoscope but also gives thefreedom to increase the length of the sensor, thus increasing imageresolution in the horizontal sense.

As will be explained below, there are two specific embodiments of therealigned sensor, each one associated with a respective design of theoptical assembly as will be described in detail below.

In addition to the above-mentioned geometrical realignment, the sensormay be supplied with color filters to allow acquisition of IR images fordiagnostic purposes or 3D imaging, again as will be described in detailbelow.

Referring now to the geometric design of the sensor, as will beappreciated, the sensor comprises a field of pixels arranged in an arrayover an image-gathering field. The first specific embodiment comprises arearrangement of the pixels in the sensor. Given that for the purposesof example, the sensor width may be divided into say two parts, then thetwo parts may be placed end to end lengthwise. Thus, for example, a512×512 pixels' sensor with pixel dimensions of 10×10 micron, may bedivided into two sections of width 256 pixels each to be placed end toend to give a sensor of 256×1024 pixels and having an overall imagingarea of 2.56 mm×10.24 mm. The longer dimension is preferably placedalong the lengthwise dimension of the endoscope, thus permitting reduceddiameter of the endoscope with no corresponding reduction in theprecision level of the image.

The second specific embodiment likewise relates to a geometricalrearrangement of the pixels. The prior art image sensor has a round orsquare overall sensor or pixilated area, however, if the same number ofpixels are arranged as a rectangle having the same area as the originalsensor but with the height and width freely chosen then the width may beselected to be smaller than the width of the equivalent prior artsensor. More particularly, for an exemplary 512×512 pixels' sensor withpixel dimensions of 10×10 micron the standard prior art sensor (whichwill have a width of 5.12 mm) may be replaced by a rectangular sensorhaving the same overall sensing area as in the previous specificembodiment, but with specific width height dimensions of 2.56 mm×10.24mm, thus becoming easier to fit in the endoscope.

Reference is now made to FIG. 5, which is a ray diagram showing asimplified view from above of optical paths within the endoscope. Aswill be appreciated, in order for the image sensors of the specificembodiments referred to above to produce images which can be recreatedin an undistorted fashion, each sensor is preferably associated with anoptical assembly which is able to redirect image parts in accordancewith the rearrangements of the pixels.

FIG. 5 shows a version of optical assembly 48 designed for the first ofthe two specific embodiments of the image sensor, namely that involvingthe widthwise transfer of pixels. A side view of the same opticalassembly is shown in FIG. 6. FIG. 5 shows a point source object 80, fromwhich light reaches two lenses 82 and 84. The two lenses are selectedand arranged to divide the light into two parts, which parts reach afront-surface-mirror 86. The front surface mirror sends each part of theimage to a different part of the sensor 46, and recovery of the image ispossible by appropriate wiring or addressing of the sensor pixels torecover the original image shape.

Reference is now made to FIG. 7 which is a ray diagram showing analternative version of optical assembly 48, again designed for the firstspecific embodiment of the image sensor. A single lens 86 is positionedin conjunction with two front-surface-mirrors 88 and 90 to deflect lightfrom the object 80 to the mirrors. Each of the two front surface mirrorsrespectively transfers half of the image to the upper or lower part ofthe sensor 46.

Reference is now made to FIG. 8, which is a ray diagram showing a thirdembodiment of the optical assembly 48, this time for the second of thespecific embodiments of the image sensor 46, namely the embodiment inwhich the square shape of pixels is reduced to a rectangular shapehaving smaller width. An asymmetric or astigmatic lens 92 is arranged tofocus light onto a front-surface-mirror 94. The light is distorted bythe lens 92 to undo the distortion introduced into the image by therectangular shape of the sensor 46, and then it is reflected by themirror 94 onto the surface of the sensor 46.

Reference is now made to FIG. 9, which is a ray diagram taken from theside showing a further embodiment of the optical assembly 48. Theembodiment of FIG. 8 necessitates a relatively complicated design of themirror, and in order to obviate such complexity, additional optical desis shown. As shown in FIG. 9, the same astigmatic lens 92 is placed, notin front of a mirror but rather in front of a series of flat opticalplates 96 .l. . . 96 .n, each comprising a diagonal lateral crosssection, the plates each reflecting the light through the respectiveplate to the surface of sensor 46.

Reference is additionally made to FIG. 10, which is a ray diagram, takenfrom the front, of the series of optical plates 96 of FIG. 9. Acomparison between the perspectives of FIG. 9 and FIG. 10 show thelayout of the plates with respect to the endoscope.

Reference is now made to FIG. 11, which is a simplified ray diagramshowing a further embodiment of the optical assembly 48. In theembodiment of FIG. 11, a single lens 98 is preferably used to focuslight from an object 80 to a plane 100 shown in dotted lines. A seriesof optical fibers 102 are lined up over the surface of plane 100 toguide light to desired portions of the surface of the image sensor 46.The fibers 102 are able to direct light as desired and thus can be usedin combination with any arrangement of the sensor pixels that isdesired.

Returning to the construction of the image sensor 46, reference is nowmade to FIG. 12, which is a layout diagram showing a layout of pixels ona sensory surface of an embodiment of the image sensor 46. In FIG. 12,an array comprising pixels of four types is shown, red r, green g, blueb and infra-red IR. The pixels are evenly spaced and allow acquisitionof a colored image when used in conjunction with white light or an IRimage when used in conjunction with an IR source.

In many cases, important medical information is contained at IRwavelengths. In order to allow acquisition of IR images, the sensor ispreferably designed as described above, and using inter alia pixels IRfilters, that is to say color filters that have band passes at IRwavelengths. The sensor is placed in an endoscope in association witheither one or both of a source of visible light and a source ofinfra-red light. Use of the appropriate one of the two light sourcespermits acquisition of either color frames or IR frames as desired. Inone preferred embodiment, IR and color frames are obtainedsimultaneously by operating color and IR light sources together andallowing each pixel to pick up the waveband it has been designed for. Inanother preferred embodiment the color and IR light sources are operatedseparately. Typically one IR frame would be prepared and sent for everyseveral color frames.

Reference is now made to FIG. 13, which is a simplified ray diagramshowing how the endoscope may be used in a stereoscopic mode. Thestereoscopic mode permits the production of 3D images. As with previousfigures the ray diagram indicates rays emanating from a single point,and the skilled person will appreciate how to extrapolate to a fullimage.

In FIG. 13, an endoscope comprises two separate white light sources 110and 112 located at opposite sides of a front opening of the endoscope,respectively being a left light source 110 and a right light source 112.The two white light sources are controlled to light in turn insuccessive short flashes to illuminate an object 114. Light reflected bythe object 114 returns to the endoscope where it strikes a lens 115placed across the front opening and where it is focused on to the planeof sensor 46. The sensor detects the illumination level, which differsbetween the left and right light beams. The ratio of the illuminationlevels may be used to calculate the position of the object and therebyto build up a 3D distance database, as will be explained in greaterdetail below.

As mentioned above, in the stereoscopic mode the left and right lightsources are used sequentially. Comparison between left and rightilluminated images allows a 3D database to be constructed, enablingstereoscopic display of the scene. In the present embodiment, thecomparison between the images is based upon photometry measurements. InFIG. 13, an image 116 of object 114 may be considered as comprising aseries of activated x, y, locations on the detection plane of the sensor46. For each of the x, y locations forming the image 116 on the sensor46, a ratio between the Right Illuminated Image (RII) and the LeftIlluminated Image (LII) may be discerned. The detected ratio may differover the image as it is a function in each case of the distances of therespective light source to the object 114. The left light source 110 andthe right light source 112 have a distance between them which is twiced, d being the length of arrow 117, and the lens has a focal length of1/f, where f is the length of arrow 118. The distance from the lens 115to the plane of the object 114 is denoted by Z and is indicated by arrow120.

The Left Beam Length (LBL) can thus be expressed by:LBL=√[Z ²+(X−d)²]+√[(Z+1/f)²+(X+x)²]

while the Right Beam Length (RBL) is given by:RBL=√[Z ²+(X+d)²]+√[(Z+1/f)²+(X+x)²]

where:X=xZf

Thus the ratio of the light intensity between the left and right lightsources, which is the inverted square of the distance LBL/RBL, may beexpressed as:LeftToRightRatio=(LBL/RBL)⁽⁻²⁾

The image 116, obtained as described above may now be stored in terms ofa 3D model. The 3D model is preferably displayed as a 3D image byconstructing therefrom two stereoscopic images. The conversion may beperformed using conversion formulae as follows:yl=yr=−Y/(Z*f)xl=(−X−D/2)/(Z*t)xr=(−X+D/2)/(Z*f)

FIG. 13 thus shows how an image of the object can be stored as a 3D database. 3D data of the object is obtained as described above and stored asa database.

Reference is now made to FIG. 14, which is a further simplified raydiagram showing, by means of rays, how the 3D model or database of FIG.13 can be used to obtain a 3D effect at the eyes of an observer. Inorder to display the 3D information using a standard 2D display(monitor) the database is converted into two separate stereoscopicimages, and a display device is used to display each one of thestereoscopic images to a different eye. For example the device may be apair of glasses having a controllable shutter on each on of the eyes.

In FIG. 14, X, Y, 114 and Z 120 represents the three dimensions to beused in the image 119, which corresponds to image 116 as stored in theprevious figure, the object being to reproduce the three dimensionalcharacter of the image by showing different projections of the image toeach of the two eyes of a viewer.

line 122 represents a projected location on the left image.

Line 124 represents the same projected location as it appears on theright image.

1/f 118 is the focal length (the amplification factor).

D 126 is the distance between the lenses 128 (representing the eyes).

A preferred embodiment for producing a 3D model using the endoscope usesdifferent color left and right light sources in place of white lightsources. Thus, instead of sequentially illuminating the object fromeither side, it is possible to illuminate the image simultaneously usingboth sources and to use appropriate filters to separate the left andright brightness information. For example a left illumination source 110may be green and right illumination source 112 may be a combination ofred+blue. Such a two-color embodiment is advantageous in that it issimple to control and avoids image distortion problems due to the timelag between acquisitions of the two separate images.

In one alternative embodiment, one of the light sources 110, 112 is avisible light source and the second light source is an IR light source.In the case of an IR light source color filters at the sensor preferablyinclude an IR pass filter. The sensor of FIG. 12, with an arrangement ofIR, red, green and blue detectors as described above may be used.

Reference is now made to FIGS. 15A and 15B which are simplifiedschematic diagrams showing an endoscope according to a preferredembodiment of the present invention for obtaining dual sensorstereoscopic imaging, as will be explained below. FIG. 15A is a sidesectional view and FIG. 15B is a front view.

In the embodiment of FIG. 15A two image sensors 140 and 142 are situatedback to back along a plane of the central axis of an endoscope 144. Eachimage sensor 140 and 142 is associated with a respective opticalassembly comprising a lens 150 and 152 and a mirror 154 and 156. Therespective light source 146, 148, illuminates the entire field of viewas described above and light is gathered by the lens and directed by themirror onto the sensor. The sensors are preferably mounted on a singlePCB 158.

FIG. 15B is a view from the front of the endoscope of FIG. 15A. It willbe noticed that a third optical light source 158 shown. Since thestereoscopic aspect of the image is obtained from the use of two opticalimage paths, as opposed to the previous embodiments which used differentlight sources and different object optical paths, there is now freedomto use any number of light sources as desired to produce desired color(or IR) information.

The back-to-back arrangement of the sensors 140 and 142 along thecentral axis of the endoscope 144 ensures that the endoscope dimensionsare minimized both lengthwise and radially.

Reference is now made to FIG. 16, which is an alternative embodiment ofan endoscope for obtaining dual sensor stereoscopic imaging. Anendoscope 160 comprises two image sensors 162 and 164 arranged in a headto tail arrangement along one longitudinal wall of the endoscope, andagain, as above, preferably parallel to the wall and at least notperpendicular thereto. Illumination sources 166 and 168 are located at afront end 170 of the endoscope and located at the periphery thereof. Twolenses 172 and 174 direct light received from a field of view ontorespective mirrors 176 and 178 each of which is arranged to deflect thelight onto one of the sensors. Each image sensor 162 and 164 thusprovides a slightly different image of the field of view.

It is emphasized that the dual sensor configuration does not decreasethe overall image resolution, because, in accordance with the aboveconfigurations, two full-size image sensors may be used.

The two versions of an endoscope for obtaining dual sensor stereoscopicimaging described above can make use of image sensors either with orwithout color filters. However the sensor of FIG. 12 could be used forone or both of the sensors in either of the embodiments above.

A further preferred embodiment uses a monochrome sensor for one of thetwo image sensors and a color sensor for the second. Such a combinationof one monochrome sensor and one color-filtered sensor in the unitimproves the resolution of the overall image and the sensitivity anddynamic range of the endoscope.

The above embodiments have been described in accordance with the generalendoscope layout given in FIG. 1. In the following, alternativeendoscopic system configurations are described.

Reference is now made to FIG. 17, which is a simplified block diagram ofa network portable endoscope and associated hardware. Parts that areidentical to those shown above are given the same reference numerals andare not referred to again except as necessary for an understanding ofthe present embodiment. An endoscope 10 is connected to a centralcontrol unit 180 where dedicated image processing takes place. Thecontrol unit 180 allows for full motion video to be produced from thesignals emitted by the endoscope. The control unit is connected to alocal display device 182. Additionally or alternatively, a remotecontrol and viewing link 183 may be used to allow remote monitoring andcontrol of the endoscope. The endoscope 10 is preferably a portabledevice and may be powered from a battery pack 184.

Reference is now made to FIG. 18, which is a simplified block diagram ofan endoscope adapted to perform minimal invasive surgery (MIS). Partsthat are identical to those shown above are given the same referencenumerals and are not referred to again except as necessary for anunderstanding of the present embodiment. The most common use ofendoscopic systems is for the performance of MIS procedures by thesurgeon in the operating room. The use of a reduced size endoscopeaccording to the above embodiments enables new procedures to beperformed in which minimal dimensions of the operating equipment isimportant. In FIG. 18, the endoscope 10 is connected to a rack 190. Therack contains accomodation for a full range of equipment that may berequired in the course of use of the endoscope in the operating room,for example a central control unit 180, a high quality monitor 182, aninsufflator 186 etc.

The configuration of FIG. 18, by virtue of the dedicated imageprocessing provided with the control unit 180, gives full motion videowithout requiring fiber-optic and camera head cables.

Reference is now made to FIG. 19, which is a simplified block diagramshowing an enhanced version of the endoscope for use in research. Partsthat are identical to those shown above are given the same referencenumerals and are not referred to again except as necessary for anunderstanding of the present embodiment. The system comprises aminiature endoscopic front-end 10 connected to a highly integrated PCbased central control unit 200 via communication link 20.

The central control unit uses dedicated image processing and thusenables full motion video, displayable locally on display device 182 orremotely via control and display link 183. An optional printer 202 isprovided to print documents and images, including images taken via theendoscope, of the pathologies or stages of the procedure. The systempreferably includes a VCR 204 for recording video produced by theendoscope and a digital storage device 206 allowing archiving of thewhole video. As mentioned above, the system can also be connected viaremote control and viewing link 183, to a remote site for teaching orfor using medical help and guidance. In some hospitals and operatingrooms, in addition to regular operating procedures, research is carriedout. Research procedures generally require additional documentation andcommunication functions. In order to support those requirements a PCbased system with high documentation and communication capabilities isprovided by the enhanced control unit 200. In addition to the externaldevices, an image enhancement software package is used, allowing thegeneration of high quality hard copies of images.

Reference is now made to FIG. 20, which is a simplified block diagramshowing a configuration of endoscope for obtaining stereoscopic (3D)images. Parts that are identical to those shown above are given the samereference numerals and are not referred to again except as necessary foran understanding of the present embodiment. The miniature endoscope 10is connected via a communication link 20 as before to a 3D centralcontrol unit 210, which is the same as the previous control unit 200except that it has the additional capability to construct a 3D modelfrom image information provided by the endoscope. The 3D model can thenbe projected to form a 3D image on a 3D stereoscopic display system 212.The configuration of FIG. 20 may be combined with features taken fromany of the embodiments referred to above.

Recently, new operating procedures requiring stereoscopic (3D) displayhave been developed. In particular such new applications involvedminimally invasive heart and brain procedures. The 3D imagingembodiments referred to above, which may be grouped into multiple lightsource based imaging and dual optical path imaging, can give thenecessary information to construct a 3D model of the scene and togenerate stereoscopic images therefrom.

Reference is now made to FIG. 21, which is a simplified block diagramshowing a variation of an endoscope system for use in intra-vascularprocedures. Parts that are identical to those shown above are given thesame reference numerals and are not referred to again except asnecessary for an understanding of the present embodiment. The systemincludes a long, flexible, thin and preferably disposable catheter 220,a balloon/Stent 222, an endoscope imaging head 224, an X-ray tube 226,X-ray imaging system 228, a video display system 230 and an injectionunit 232.

Intra Vascular procedures are widely used in the medical field. Amongvarious intra-vascular procedures, cardiac catheterization is a verycommon diagnostic test performed thousands of times a day. During theprocedure, catheter 220 is inserted into an artery at the groin or arm.The catheter is directed retrogradely to the heart and to the origin ofthe coronary arteries, which supply blood to the heart muscle. Acontrast substance (“dye”) is injected through the catheter. The use ofan x-ray tube, and an endoscope in conjunction with the dye enables aview of the heart chambers and coronary arteries to be obtained. Theresulting images may be recorded using an x-ray camera and/or theendoscope systems as described above. If an obstruction is detected inone or more of the coronary arteries, the obstruction may be removed andthe artery reopened using techniques such as inserting the balloon andinflating it (PTCA) or inserting a stent, as known to the person skilledin the art.

In intra-vascular operation generally, a few methods may be used toacquire intra-vascular images in the presence of blood. One method isbased on the fact that certain near IR wavelengths allow viewing throughblood. The method thus involves the use of an IR illumination source anda sensor with IR filters as described above. Another method usescontrolled injection of a transparent physiological liquid into theblood vessel in order to dilute the blood prior to the imaging. Yetanother method uses a conical dome, a balloon or any other rigid orflexible and inflatable transparent structure in order to improvevisibility by “pushing” the blood to the walls of the vessels, thusenlarging the part of the optical path that does not include blood.Another way of improving visibility is by using a post-processingalgorithm after the acquiring of the image has been done. Thepost-processing algorithm is based on the extraction of parameters fromthe received image and the use of those parameters in an inverseoperation to improve the image.

There is thus provided an endoscope of reduced dimensions which is ableto provide 2D and 3D images, and which is usable in a range of minimallyinvasive surgical procedures.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather the scope of the present invention isdefined by the appended claims and includes both combinations andsubcombinations of the various features described hereinabove as well asvariations and modifications thereof which would occur to personsskilled in the art upon reading the foregoing description.

1. An endoscope that gathers light, the endoscope having a longitudinaldimension along which the endoscope has a tubular cross-section with aninternal diameter, the endoscope comprising: at least one imagedistorter, and at least one image sensor disposed within the endoscopeat a location characterized by the cross-section, said at least oneimage sensor having a rectangular sensing field, the rectangular sensingfield having an image resolution level and having a maximum diagonaldimension that is greater than the endoscope's internal diameter, andsaid at least one image distorter distorting the gathered light so as toproject a distorted image on said sensing field, so that said distortedimage is sensible at said image sensor substantially with the imageresolution level.
 2. An endoscope according to claim 1, wherein saidimage distorter comprises an image splitter operable to split said imageinto two part images.
 3. An endoscope according to claim 2 wherein saidimage sensor comprises two sensor parts, each separately arranged alonglongitudinal walls of said endoscope.
 4. An endoscope according to claim3, wherein said two parts are arranged in successive lengths alongopposite longitudinal walls of said endoscope.
 5. An endoscope accordingto claim 1, wherein said distorter is an astigmatic image distorter. 6.An endoscope according to claim 1, wherein said image distorter is animage rectangulator such that the distorted image is a rectangulatedimage.
 7. An endoscope according to claim 6, wherein said sensing fieldhas a rectangular shape substantially complementary to the rectangulatedimage, as projected by the image distorter.
 8. An endoscope according toclaim 1, wherein said image distorter comprises at least one lens.
 9. Anendoscope according to claim 8, wherein said image distorter comprisesat least one image-distorting mirror.
 10. An endoscope according toclaim 9, wherein said image distorter comprises at least a secondimage-distorting mirror.
 11. An endoscope according to claim 8, whereinsaid image distorter comprises optical fibers to guide image lightsubstantially from said lens to said image sensor.
 12. An endoscopeaccording to claim 8, wherein said image distorter comprises a secondlens.
 13. An endoscope according to claim 8, wherein said imagedistorter comprises at least one flat optical plate.
 14. An endoscopeaccording to claim 1, further comprising at least one light source forilluminating an object, said light source being controllable to flash atpredetermined times.
 15. An endoscope according to claim 14 furthercomprising a second light source, said first and said second lightsources each separately controllable to flash.
 16. An endoscopeaccording to claim 15, wherein said first light source is a white lightsource and said second light source is an a source of invisible lightradiation.
 17. An endoscope according to claim 16, wherein said secondlight source is an IR source.
 18. An endoscope according to claim 17,one light source comprising light having a first spectral response andthe other light source comprising light having a second spectralresponse.
 19. An endoscope according to claim 16, wherein said secondlight source is a UV light source.
 20. An endoscope according to claim15, one light source being a right side light source for illuminating anobject from a first side and the other light source being a left sidelight source for illuminating said object from a second side.
 21. Anendoscope according to claim 20 further comprising color filtersassociated with said light gatherer to separate light from said imageinto right and left images to be fed to respective right and leftdistance measurers to obtain right and left distance measurements forconstruction of a three-dimensional image.
 22. An endoscope according toclaim 20, said light sources being configured to flash alternately. 23.An endoscope according to claim 20, further comprising a relativebrightness measurer for obtaining relative brightnesses of points ofsaid object using respective right and left illumination sources,thereby to deduce 3 dimensional distance information of said object foruse in construction of a 3 dimensional image thereof.
 24. An endoscopeaccording to claim 14, further comprising a image gatherer and a secondimage sensor.
 25. An endoscope according to claim 24, wherein one ofsaid image sensors is a color image sensor and a second of said imagesensors is a monochrome image sensor.
 26. An endoscope according toclaim 24, wherein said first and said second image sensors are arrangedback to back longitudinally within said endoscope.
 27. An endoscopeaccording to claim 24, wherein said first and said second image sensorsare arranged successively longitudinally along said endoscope.
 28. Anendoscope according to claim 27, wherein said first and said secondimage sensors are arranged along a longitudinal wall of said endoscope.29. An endoscope according to claim 1, comprising a brightness averageroperable to identify brightness differentials due to variations indistances from said endoscope of objects being illuminated, andsubstantially to cancel said brightness differentials.
 30. An endoscopeaccording to claim 29, further comprising at least one illuminationsource for illuminating an object with controllable width light pulsesand wherein said brightness averager is operable to cancel saidbrightness differentials by controlling said widths.
 31. An endoscopeaccording to claim 1, having at least two controllable illuminationsources, one illumination source for emitting visible light to produce avisible spectrum image and one illumination source for emittinginvisible light to produce a corresponding spectral image, saidendoscope being controllable to produce desired ratios of visible andinvisible corresponding spectral images.
 32. An endoscope according toclaim 1, wherein said sensing field has a first field dimension and asecond field dimension, the first field dimension being less than orequal to the second field dimension, and wherein said at least one imagesensor is disposed within said endoscope so that the first fielddimension has a dimensional component transverse to the endoscope'slongitudinal dimension.
 33. An endoscope according to claim 32, whereinthe first field dimension is less than or equal to the endoscope'sdiameter.
 34. An endoscope according to claim 32, wherein said at leastone image sensor is disposed within said endoscope so that the secondfield dimension has a dimensional component along or parallel to theendoscope's longitudinal dimension.
 35. An endoscope according to claim32, wherein said at least one image sensor is disposed within saidendoscope so that the second field dimension has a dimensional componentother than along or parallel to the endoscope's longitudinal dimension.36. An endoscope according to claim 1, wherein said at least one imagedistorter is arranged so as to project the distorted image substantiallyover the sensing field.
 37. An endoscope system, the system comprising:an endoscope and image processor; said endoscope gathering light, andhaving a longitudinal dimension along which the endoscope has a tubularcross-section with an internal diameter, the endoscope including atleast one image sensor disposed within the endoscope at a locationcharacterized by the cross-section, and having a rectangular sensingfield, the rectangular sensing field having an image resolution leveland having a maximum diagonal dimension that is greater than theendoscope's internal diameter, and at least one image distorter, said atleast one image distorter distorting the gathered light so as to projecta distorted image on said sensing field, so that the distorted image issensible at said image sensor with substantial retention of the imageresolution level; and said image processor operable for processing imageoutput of said endoscope.
 38. An endoscope system according to claim 37,wherein said image processor is a motion video processor operable toproduce motion video from said image output.
 39. An endoscope systemaccording to claim 37, wherein said image processor comprises a 3Dmodeler for generating a 3D model from said image output.
 40. Anendoscope system according to claim 39, wherein said image processorfurther comprises a 3D imager operable to generate a stereoscopicdisplay from said 3D model.
 41. An endoscope system according to claim37, further comprising an image recorder for recording imaging.
 42. Anendoscope system according to claim 37, further comprising a control anddisplay communication link for remote control and remote viewing of saidsystem.
 43. An endoscope system according to claim 37, wherein saidimage distorter comprises an image splitter operable to split said imageinto two part images.
 44. An endoscope system according to claim 37,wherein said image sensor comprises two sensor parts, each separatelyarranged along longitudinal walls of said endoscope.
 45. An endoscopesystem according to claim 44, wherein said two parts are arranged insuccessive lengths along opposite longitudinal walls of said endoscope.46. An endoscope system according to claim 37, wherein said imagedistorter is an astigmatic image distorter.
 47. An endoscope systemaccording to claim 37, wherein said image distorter is an imagerectangulator such that the distorted image is a rectangulated image,and wherein said sensing field has a rectangular shape substantiallycomplementary to the rectangulated image, as projected on said sensingfield.
 48. An endoscope system according to claim 47, wherein said imagedistorter comprises at least one flat optical plate.
 49. An endoscopesystem according to claim 48, further comprising a second light source,said first and said second light sources each separately controllable toflash.
 50. An endoscope system according to claim 49, one light sourcebeing a right side light source for illuminating an object from a firstside and the other light source being a left side light source forilluminating said object from a second side.
 51. An endoscope systemaccording to claim 50, one light source comprising light of a firstspectral response and the other light source comprising light of asecond spectral response.
 52. An endoscope system according to claim 51,further comprising color filters associated with said light gatherer toseparate light from said image into right and left images to be fed torespective right and left distance measurers to obtain right and leftdistance measurements for construction of a three-dimensional image. 53.An endoscope system according to claim 51, said light sources beingconfigured to flash alternately.
 54. An endoscope system according toclaim 51, said light sources being configured to flash simultaneously.55. An endoscope system according to claim 51, further comprising arelative brightness measurer for obtaining relative brightnesses ofpoints of said object using respective right and left illuminationsources, thereby to deduce 3 dimensional distance information of saidobject for use in construction of a 3 dimensional image thereof.
 56. Anendoscope system according to claim 55, wherein said first and saidsecond image sensors are arranged back to back longitudinally withinsaid endoscope.
 57. An endoscope system according to claim 56, whereinsaid first and said second image sensors are arranged along alongitudinal wall of said endoscope.
 58. An endoscope system accordingto claim 55, wherein said first and said second image sensors arearranged successively longitudinally along said endoscope.
 59. Anendoscope system according to claim 37, further comprising at least onelight source for illuminating an object.
 60. An endoscope systemaccording to claim 59, wherein said first light source is a white lightsource and said second light source is an invisible light source.
 61. Anendoscope system according to claim 59, further comprising a secondimage gatherer and a second image sensor.
 62. An endoscope systemaccording to claim 37, wherein said image distorter comprises at leastone lens.
 63. An endoscope system according to claim 62, wherein saidimage distorter comprises at least one image-distorting mirror.
 64. Anendoscope according to claim 62, wherein said image distorter comprisesoptical fibers to guide image light substantially from said lens to saidimage sensor.
 65. An endoscope system according to claim 62, whereinsaid image distorter comprises a second lens.
 66. An endoscope systemaccording to claim 62, wherein said image distorter comprises at least asecond image-distorting mirror.
 67. An endoscope system according toclaim 37, comprising a brightness averager operable to identifybrightness differentials due to variations in distances from saidendoscope of objects being illuminated, and substantially to reduce saidbrightness differentials.
 68. An endoscope having a longitudinaldimension along which the endoscope has a tubular cross-section with aninternal diameter, the endoscope gathering an optical image via light ofa field of view, said optical image characterized by resolution anddynamic range parameters corresponding to proper image acquisitionthereof, the endoscope comprising: an image distorter and an imagesensor, the image sensor having a substantially rectangular sensingfield comprising a sensing surface, the sensing surface having a sensingarea supporting resolution and dynamic range substantially compatiblewith the optical image's resolution and dynamic range parameters, andthe image sensor being disposed within said endoscope at a locationcharacterized by the cross-section so that the sensing surface has se adimensional component along or parallel to the endoscope's longitudinaldimension, and the image distorter distorting the gathered lightsubstantially into a rectangular shape and projecting such distortedlight to the image sensor, so as to form an image on said sensing field,the formed image having an area larger than the endoscope'scross-sectional area as determined by the internal diameter.
 69. Anendoscope according to claim 68, further comprising a contrast equalizerfor compensating for high contrasts differences due to differentialdistances of objects in said field of view.
 70. An endoscope accordingto claim 68, comprising two illumination sources for illuminating saidfield of view.
 71. An endoscope according to claim 70, said illuminationsources being controllable to illuminate alternately, and said imagesensor being controllable to gather images in synchronization with saidillumination sources thereby to obtain independently illuminated images.72. An endoscope according to claim 70, each illumination source havinga different predetermined spectral response.
 73. An endoscope accordingto claim 72, said image sensor comprising pixels, each pixel beingresponsive to one of said predetermined spectral responses.
 74. Anendoscope according to claim 68, said image sensor comprising aplurality of pixels responsive to white light.
 75. An endoscopeaccording to claim 68, said image sensor comprising a plurality ofpixels responsive to different wavelengths of light.
 76. An endoscopeaccording to claim 75, said wavelengths comprising at least three of redlight, green light, blue light and infra-red light.
 77. An endoscopeaccording to claim 68, further comprising a second image sensor forforming a second image from light obtained from said field of view. 78.An endoscope according to claim 77, wherein one of said image sensors isa color sensor and a second of said image sensors is a monochromesensor.
 79. An endoscope according to claim 77, said second image sensorbeing placed in back to back relationship with said first image sensorover a longitudinal axis of said endoscope.
 80. An endoscope accordingto claim 77, said second image sensor being placed in end to endrelationship with said first image sensor along a longitudinal wall ofsaid endoscope.
 81. An endoscope according to claim 77, said secondimage sensor being placed across from said first image sensor on facinginternal longitudinal walls of said endoscope.
 82. An endoscopeaccording to claim 68, wherein said image distorter comprises aplurality of optical fibers for guiding parts of a received image tosaid image sensor.
 83. An endoscope according to claim 68, wherein saidsensing field has a first field dimension and a second field dimension,the first field dimension being less than or equal to the second fielddimension, and wherein said at least one image sensor is disposed withinsaid endoscope so that the first field dimension has a dimensionalcomponent transverse to the endoscope's longitudinal dimension.
 84. Anendoscope according to claim 83, wherein the first field dimension isless than or equal to the endoscope's diameter.